math help

What is 28/100 + 2/7?

What is 28/100 + 2/7?

Here's how we add

28
100
+
2
7

Step 1

We still have different denominators (bottom numbers), though, so we need to get a common denominator. This will make the bottom numbers match. Multiply the denominators together first. Now, multiply each numerator by the other term's denominator.

Now we multiply 28 by 7, and get 196, then we multiply 100 by 7 and get 700.

28/100 times 7

Now for the second term. You multiply 2 by 100, and get 200, then multiply 100 by 7 and get 700.

2/7 times 100

This gives us a new problem that looks like so:

196
700
+
200
700

Step 2

Since our denominators match, we can add the numerators.

196 + 200 = 396

That gives us an answer of

396
700

Step 3

Can this fraction be reduced?

First, we attempt to divide it by 2...

Are both the numerator and the denominator evenly divisible by 2? Yes! So we reduce it:

396
700
÷ 2 =
198
350

So far so good... let's try to divide by that number again.

Are both the numerator and the denominator evenly divisible by 2? Yes! So we reduce it:

198
350
÷ 2 =
99
175

So far so good... let's try to divide by that number again.

No good. So next you try the next prime number, which is 3...

No good. So next you try the next prime number, which is 5...

No good. So next you try the next prime number, which is 7...

No good. So next you try the next prime number, which is 11...

No good. So next you try the next prime number, which is 13...

No good. So next you try the next prime number, which is 17...

No good. So next you try the next prime number, which is 19...

No good. So next you try the next prime number, which is 23...

No good. So next you try the next prime number, which is 29...

No good. So next you try the next prime number, which is 31...

No good. So next you try the next prime number, which is 37...

No good. So next you try the next prime number, which is 41...

No good. So next you try the next prime number, which is 43...

No good. So next you try the next prime number, which is 47...

No good. So next you try the next prime number, which is 53...

No good. So next you try the next prime number, which is 59...

No good. So next you try the next prime number, which is 61...

No good. So next you try the next prime number, which is 67...

No good. So next you try the next prime number, which is 71...

No good. So next you try the next prime number, which is 73...

No good. So next you try the next prime number, which is 79...

No good. So next you try the next prime number, which is 83...

No good. So next you try the next prime number, which is 89...

No good. So next you try the next prime number, which is 97...

No good. So next you try the next prime number, which is 101...

No good. 101 is larger than 99. So we're done reducing.

And we're done! Here's the final answer to 28/100 + 2/7

28
100
+
2
7
=
99
175
© 2014 Randy Tayler